Circuit-controlling device



June 1930. L. L. CUNNINGHAM CIRCUIT CONTROLLING DEVICE Original Filed Feb. 8, 1926 2 Sheets-Sheet 1 Inventor LEWIS L.CUNNIN6HAM Aboor-neys uivw I I RI! June 10, 1930. L. L. CUNNINGHAM 7 3,

- CIRCUIT CONTROLLING DEVICE Original Filed Feb. 8, 1926 ZShoets-Sheet 2 Inventor- LEW/5 L. CUNNINGHAM dd/gunner;

A error-n egg been connected for operation by a dia- Patented Jung: 10, 1930 UNITED STATES PATENT OFFICE SIGNMENTS, TO MINNEAPOLIS-HONEYWELL REGULATOR COMPANY, 01' MINNE- APOLIS, MINNESOTA, A CORPORATION OF DELAWARE CIRCUIT-CONTROLLING DEVICE Original application filed February 8, 1928, Serial No. 86,849. Divided and this application flied October 26, 1927. Serial No. 228,855.

This invention relates to im rovements in phragmatic element which forms part of a circuit controlling devices, and of my co endin application for automatic ranged and mounted so that its deflection devices, led F ebruary 8th, 1926, Serial can be constantly maintained by radiant Number 86,849. rays regardless of the degree of temperature An important objet is to provide means or the. amount of radiant energy impinging whereby the operation of a contact member. it. The manner of mounting the diaphragm by a control device, is obtained so that a stpp forms subject matter of the copending apengagement of the contactmembe'r with a plication above mentioned. However, for contact point will allow continued movement the sake of clearness, the elements of the of the control, element, without breakage of construction are described, so that the device the contact member. The device provides may be illustrated in an environment, for means capable of operation by a diaphragm which it is very well adapted. as a thermostatic element, in such manner The elements 1 and 9 constitute respecthat the initial movement. of the thermotively means for guiding or'directing the static member in either direction will imrays against a diaphragm, and for supportis divisional construction wherein the diaphragm is armediately cause the contact member to make ing the herein claimed device. The member or break an electrical circuit, the arrange- 1 has flanges 2 and 3, the flange 3 being ment further being such that after this make provided for attaching the device to the door or break, further movement of the thermoof a furnace. The member 9 has a flange static element in the same direction can take 4, the flanges 4 and 2 being of substantially place without a corresponding movement of the same diameter. A ring 5 is interposed the contact member. between the members as shown and between Features of the invention include the this ring and the flah'g e 4 is interposed the means for connecting a contact member with diaphragm 6. The elements 4, 6 and 5 are its controlling element, as well as means for. secured together by means of screws or bolts.

supporting the contact element in relation The casing 9 as a support and enclosure to its contacts. Features of the invention for the device herein claimed, is of tubular include all the details of construction for formation and provides a depressi'bn 12 exmounting and connectingt-he parts, as well ftending in an axial direction inwardly from as the specific arrangement.

Objects, advantages and features of the invention will be set forth in the description of the drawings forming apart of this application and in said drawings: igure 1 is a side elevation; .Figure 2 is a longitudinally vertical section; r

Figure 3 isa cross section on line '33 of F i re'2;

igure 4 is a cross section on line 44 of Fi re 2;

igure 5 is a plan section on line 55 of Fi re 1; and' igure 6 isa fragmentary vertical longitudinal section illustrating a modification in which a second diaphragm as a shield and focusing device is employed.

In order to illustrate the device, it has which engage corresfponding depressions 14" on opposite sides 0 a hub or shaft 15 of contact element or control lever or arm 16. Bymeans of the screws 15, the arm 16 is thus pivoted betweenthe lugs for oscillation. The diameter of'the hub or, shaft rnay be decreased or increased. The arm is attached at one side of the hub 15. The

hub is of sufiicient diamet r to'provide the ice proper amount 1 of surface contact for a page er ribbon 17 The object is to provide su cient contact, to allow slip-- between the elements under certain conditions to be mentioned. One end of this ribbon, orfriction element, is attached substantially centrally of the diaphragm as at 18. At the opposite end the ribbon or frictional member is attached to a coil spring 20 which is in turn attached under tension to a headed plug 21 engaged in an opening 22 of the casing 9. The lower end of the plug is provided with prongs which are turned outwardly, after insertion, of the plug, to prevent its accidental movement when adjusted in an length of cop spring to maintain yieldable frictional contact between the hub and ribbon is thus or by lengthening the lever or contact element' 16. Moreover, inasmuch as the tensioned ribbon exerts a certain deflectionproducing action upon the diaphragm, the diaphragm Qwill be caused to deflect in. direction of tension of the spring when radiant energy impinges its opposite side. Thus there are two functions performed by ten sioning the element 17.

- 9.7 The opposite unattached arm 0 this" spring has a contact knob or button en-.

The casing 9 is shouldered as at 20* and engaged against theigggoulder is a disk 21 of non-onductingmaterial. -This disk has an opening 22, across which pro'ects the arm of a terminal element 23, see igure 4. This terminal element is suitably connected by a screw to the disk and has a binding screw 25 engaged therewith for securing a wire. This arm 23 has a horizontally arranged terminal extension upon which is secured by one arm as at 26, a substantially U-shaped contact-or circuit makings ring gageable with a similar button carried by a terminal extension of a second terminal element,29, each terminal element 23 and 29 having "a bindin' screw 25, see Figure 4. The outer end 0 the arm 16 is, inthis'instance, en aged against the spring element 27, norma lyin a manner to keep the contact buttons from engaging to close the cir- ,cuit. The arm 16 is electrically insulated from the hub 16 and is suitably secured to the hub in this instance, by being attached toone face ofthe same, see Figures3 and '5. The contact s ring 27 is, in this instanoernormally eld compressed by engagement of the outerfend of the arm 16 axial direction; Means for adjusting the tension of the slippage between the hub This arrangement applies the pressure at a points diametric in relation to the button. As the. diaphragm is deflected in direction of the element 9, the arm is rotated in clockwise direction to release the upper arm of the spring and permit it to contact the button of the element 29. A suitable boss 30 is suitably interiorly threaded to receive a pipe in which the wires are housed. This pipe is arranged so that the wires are rought vertically downwardly to enter it.

The spring 20 is normally under slight tension such as to condition the diaphragm to travel in a direction awa from the source of radiant energy. In this instance, the free arm of the spring 27 travels upwardly, and a depression of the spring breaks the electrical circuit. The spring 20 acts to maintain the frictional contact between the bar or hub or shaft of the lever of the contact arm 16, and yetpermits'a slippage between the two when the travel of the diaphragm is greater than is needed, this to prevent breakage of the aim 16 due to overrunning. Thus it will be seen that if the movement of the diaphragm in direction away from the source of radiant energy is greater than is needed, for the upward movement of the outer end of the lever 16, and element 17 will take place to prevent breakage. The

1 means thus provided is compensatory in nature and at the same time provides for the positive operation of the contact device 1 as the result of .movement of the diaphragm in either direction. Therefore, it will be seen that when heat is applied to the dia-"' phragm, the element 17 being frictionally engaged with the hub will rotate the arm against the tension of the spring 20. As

the diaphragm continues to move after the outer end of the arm 16 has engaged the upper contact, '50 it can move no farther, the action of the spring will take up slack in the element 17 so that this element simply slides or slips \over or along-the surface of the hub or shaft. When the diaphragm cools and exerts a pull in the opposite direction to exert a greatertension on the spring, the hub will be rotated in an oppo-' siteor counter-clockwise direction and the contact broken as the result of depression of the spring27 by the outer end of the arm 16. If the diaphragm'sho'uld continue to move inthe same direction after movement of, the outer end of the arm 16 has been sto d b the bracket then sli a takes pla betvzeen the hub. imd the as in the first place, and breakage is prevented.

- The use of the hub or shaft and frictional engagement of an element therewith, which is connected at one end with the diaphragm and is tensionally held at the opposite end,

is believed to be a novel feature.

The features of the invention, however, as before stated, include the arrangement of the outer end of the arm 16 or its'e 'uivalent in relation to the contacts a131- thes ring element 27. Althou h the specific etails of construction are c aimed, it is to be understood that the broad features of the invention relate particularly to the means whereby over movementof the control element 16 does not permit the arm to be broken, because of its engagement with either one of the contacts, as a stop, to prevent its further movement. It is conceives ble that the element 16 itself might be a conducting element, and might be arranged to operate with only one contact, and wlthout the use of the sprin 27.

' Therefore, although it is intended to claim all the details of construction, it is not intended to be limited only to those de-' tails, frictionally operable compensatory varrangement for preventing breakage by over movement of the control element,and to permit continued movement of a control but to also claim broadly the flexiblefrictionally engaging theflhub and having I one end attachedto the expansible element and the other yieldably connected to the support, the arran ement being such that I when the expansib e element moves in one direction the pivoted arm releases the resil-.

iently actuated contact, the arm being free element after further movement of the con-j ing a frame, a diaphragm, tacts onehaving the form of an expansible v a expansion, said arm havin tionally engaging the hub an trolled element has been prevented.

I- claim as my invention:

1. A device o'f the class described comprisa pair of conspring, an arm en ageable between the contacts and engagea le, by the spring during element attached to the diap ra m and frichaving its opposite ,end yieldably connected to the frame. a

v2. A device of the class described including a diaphragm, an expansible spring, as a contact-making member, able by the spring during ex ansion, a pivoted armhaving a hub, sai arm engaged with the spring for compressing the same upon rotation of the hub, a band frictiona ly engaging the peripheryaof the hub under tension aving one end yieldably su rted, and the op 'te end attachedsto t e iaphragm, wherempon movement of the diaphragm the movement of the band would cause corresponding-movement of the'arm, to allow expansion of or to compress the spring, and whereb when the motion of the arm is revented, s 'p age between the band and hu will (liaphra permit urther motion of the said contact element-in a manner to move it against its resilient "force, said arm havin a hub co-axial with its fpivotal point, a ban a hub and an a contact engage- 

